LibWeb+UI+WebContent: Pipe pinch events from AppKit UI to WebContent

Author: https://github.com/kalenikaliaksandr
Commit: c630de17ab
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6430
Reviewed-by: https://github.com/gmta
Reviewed-by: https://github.com/konradekk

Libraries/LibWeb/HTML/EventLoop/EventLoop.cpp

@@ -290,6 +290,9 @@ void EventLoop::process_input_events() const
                 },
                 [&](Web::DragEvent& drag_event) {
                     return page.handle_drag_and_drop_event(drag_event.type, drag_event.position, drag_event.screen_position, drag_event.button, drag_event.buttons, drag_event.modifiers, move(drag_event.files));
+                },
+                [&](Web::PinchEvent&) {
+                    return EventResult::Dropped;
                 });
 
             for (size_t i = 0; i < event.coalesced_event_count; ++i)

Libraries/LibWeb/Page/InputEvent.cpp

@@ -105,3 +105,19 @@ ErrorOr<Web::DragEvent> IPC::decode(Decoder& decoder)
 
     return Web::DragEvent { type, position, screen_position, button, buttons, modifiers, move(files), nullptr };
 }
+
+template<>
+WEB_API ErrorOr<void> IPC::encode(Encoder& encoder, Web::PinchEvent const& event)
+{
+    TRY(encoder.encode(event.position));
+    TRY(encoder.encode(event.scale_delta));
+    return {};
+}
+
+template<>
+WEB_API ErrorOr<Web::PinchEvent> IPC::decode(Decoder& decoder)
+{
+    auto position = TRY(decoder.decode<Web::DevicePixelPoint>());
+    auto scale_delta = TRY(decoder.decode<double>());
+    return Web::PinchEvent { position, scale_delta };
+}

Libraries/LibWeb/Page/InputEvent.h

@@ -85,7 +85,12 @@ struct WEB_API DragEvent {
     OwnPtr<BrowserInputData> browser_data;
 };
 
-using InputEvent = Variant<KeyEvent, MouseEvent, DragEvent>;
+struct WEB_API PinchEvent {
+    Web::DevicePixelPoint position;
+    double scale_delta;
+};
+
+using InputEvent = Variant<KeyEvent, MouseEvent, DragEvent, PinchEvent>;
 
 struct QueuedInputEvent {
     u64 page_id { 0 };
@@ -115,4 +120,10 @@ WEB_API ErrorOr<void> encode(Encoder&, Web::DragEvent const&);
 template<>
 WEB_API ErrorOr<Web::DragEvent> decode(Decoder&);
 
+template<>
+WEB_API ErrorOr<void> encode(Encoder&, Web::PinchEvent const&);
+
+template<>
+WEB_API ErrorOr<Web::PinchEvent> decode(Decoder&);
+
 }

Libraries/LibWebView/ViewImplementation.cpp

@@ -214,6 +214,9 @@ void ViewImplementation::enqueue_input_event(Web::InputEvent event)
             cloned_event.files = move(event.files);
 
             client().async_drag_event(m_client_state.page_index, cloned_event);
+        },
+        [this](Web::PinchEvent const& event) {
+            client().async_pinch_event(m_client_state.page_index, event);
         });
 }
 

Services/WebContent/ConnectionFromClient.cpp

@@ -245,6 +245,11 @@ void ConnectionFromClient::drag_event(u64 page_id, Web::DragEvent event)
     enqueue_input_event({ page_id, move(event), 0 });
 }
 
+void ConnectionFromClient::pinch_event(u64 page_id, Web::PinchEvent event)
+{
+    enqueue_input_event({ page_id, move(event), 0 });
+}
+
 void ConnectionFromClient::enqueue_input_event(Web::QueuedInputEvent event)
 {
     m_input_event_queue.enqueue(move(event));

Services/WebContent/ConnectionFromClient.h

@@ -75,6 +75,7 @@ private:
     virtual void key_event(u64 page_id, Web::KeyEvent) override;
     virtual void mouse_event(u64 page_id, Web::MouseEvent) override;
     virtual void drag_event(u64 page_id, Web::DragEvent) override;
+    virtual void pinch_event(u64 page_id, Web::PinchEvent) override;
     virtual void ready_to_paint(u64 page_id) override;
     virtual void debug_request(u64 page_id, ByteString, ByteString) override;
     virtual void get_source(u64 page_id) override;

Services/WebContent/WebContentServer.ipc

@@ -44,6 +44,7 @@ endpoint WebContentServer
     key_event(u64 page_id, Web::KeyEvent event) =|
     mouse_event(u64 page_id, Web::MouseEvent event) =|
     drag_event(u64 page_id, Web::DragEvent event) =|
+    pinch_event(u64 page_id, Web::PinchEvent event) =|
 
     debug_request(u64 page_id, ByteString request, ByteString argument) =|
     get_source(u64 page_id) =|

UI/AppKit/Interface/LadybirdWebView.mm

@@ -55,6 +55,7 @@ struct HideCursor {
 @property (nonatomic, strong) NSMenu* select_dropdown;
 @property (nonatomic, strong) NSTextField* status_label;
 @property (nonatomic, strong) NSAlert* dialog;
+@property (nonatomic, strong) NSMagnificationGestureRecognizer* pinch_recognizer;
 
 // NSEvent does not provide a way to mark whether it has been handled, nor can we attach user data to the event. So
 // when we dispatch the event for a second time after WebContent has had a chance to handle it, we must track that
@@ -122,6 +123,10 @@ struct HideCursor {
 
         [self registerForDraggedTypes:[NSArray arrayWithObjects:NSPasteboardTypeFileURL, nil]];
 
+        self.pinch_recognizer = [[NSMagnificationGestureRecognizer alloc] initWithTarget:self
+                                                                                  action:@selector(onPinch:)];
+        [self addGestureRecognizer:self.pinch_recognizer];
+
         m_modifier_flags = 0;
     }
 
@@ -1155,4 +1160,31 @@ struct HideCursor {
     return NO;
 }
 
+- (void)onPinch:(NSMagnificationGestureRecognizer*)recognizer
+{
+    double scale_delta = 0;
+    switch (recognizer.state) {
+    case NSGestureRecognizerStateBegan:
+        m_web_view_bridge->pinch_state() = { .previous_scale = recognizer.magnification };
+        break;
+    case NSGestureRecognizerStateChanged:
+        scale_delta = recognizer.magnification - m_web_view_bridge->pinch_state()->previous_scale;
+        m_web_view_bridge->pinch_state()->previous_scale = recognizer.magnification;
+        break;
+    case NSGestureRecognizerStateEnded:
+    case NSGestureRecognizerStateCancelled:
+        scale_delta = recognizer.magnification - m_web_view_bridge->pinch_state()->previous_scale;
+        m_web_view_bridge->pinch_state() = {};
+        break;
+    default:
+        return;
+    }
+
+    NSPoint point = [recognizer locationInView:self];
+    Web::PinchEvent pinch_event;
+    pinch_event.position = Ladybird::ns_point_to_gfx_point(point).to_type<Web::DevicePixels>() * m_web_view_bridge->device_pixel_ratio();
+    pinch_event.scale_delta = scale_delta;
+    m_web_view_bridge->enqueue_input_event(move(pinch_event));
+}
+
 @end

UI/AppKit/Interface/LadybirdWebViewBridge.cpp

@@ -79,6 +79,11 @@ void WebViewBridge::enqueue_input_event(Web::KeyEvent event)
     ViewImplementation::enqueue_input_event(move(event));
 }
 
+void WebViewBridge::enqueue_input_event(Web::PinchEvent event)
+{
+    ViewImplementation::enqueue_input_event(move(event));
+}
+
 Optional<WebViewBridge::Paintable> WebViewBridge::paintable()
 {
     Gfx::Bitmap const* bitmap = nullptr;

UI/AppKit/Interface/LadybirdWebViewBridge.h

@@ -36,6 +36,7 @@ public:
     void enqueue_input_event(Web::MouseEvent);
     void enqueue_input_event(Web::DragEvent);
     void enqueue_input_event(Web::KeyEvent);
+    void enqueue_input_event(Web::PinchEvent);
 
     struct Paintable {
         Gfx::Bitmap const& bitmap;
@@ -45,6 +46,8 @@ public:
 
     Function<void()> on_zoom_level_changed;
 
+    auto& pinch_state() { return m_pinch_state; }
+
 private:
     WebViewBridge(Vector<Web::DevicePixelRect> screen_rects, float device_pixel_ratio, u64 maximum_frames_per_second);
 
@@ -55,6 +58,11 @@ private:
 
     Vector<Web::DevicePixelRect> m_screen_rects;
     Gfx::IntSize m_viewport_size;
+
+    struct PinchState {
+        double previous_scale { 1.0 };
+    };
+    Optional<PinchState> m_pinch_state;
 };
 
 }